Single board should fly to last pin added - when adding new pin, update center on board to new coordinates

[destinmcmurry]

Instead of zooming to the original center (especially for a road trip style trip, I think it should just zoom to the last pin and maybe further out as well) - also, it would be cool to somehow set the fly over start to be the user's real location instead of NYC (and that way when they're actually there it won't have to keep flying over)